<?php namespace October\Rain\Config;

interface LoaderInterface
{

    /**
     * Load the given configuration group.
     *
     * @param  string  $environment
     * @param  string  $group
     * @param  string  $namespace
     * @return array
     */
    public function load($environment, $group, $namespace = null);

    /**
     * Determine if the given configuration group exists.
     *
     * @param  string  $group
     * @param  string  $namespace
     * @return bool
     */
    public function exists($group, $namespace = null);

    /**
     * Add a new namespace to the loader.
     *
     * @param  string  $namespace
     * @param  string  $hint
     * @return void
     */
    public function addNamespace($namespace, $hint);

    /**
     * Returns all registered namespaces with the config
     * loader.
     *
     * @return array
     */
    public function getNamespaces();

    /**
     * Apply any cascades to an array of package options.
     *
     * @param  string  $environment
     * @param  string  $package
     * @param  string  $group
     * @param  array   $items
     * @return array
     */
    public function cascadePackage($environment, $package, $group, $items);
}
